Mega Solar Concentrators
We occasionally get press releases from a group known as Trans-Mediterannean Renewable Energy Cooperation (TREC) or TREC UK, visionary proponants of massive development of solar concentrators combined with large scale new HVDC (high voltage direct current) transmission corridors.
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| Parabolic solar thermal collectors (2 axis). (Photo: TREK UK) |
According to pro-TREC sources, an area of 254 kilometers x 254 kilometers of hot desert, if covered with concentrating solar power plants, would provide electricity equivalent to the current annual electricity consumption of the whole world.
Needless to say we decided to crunch the numbers on that one.
If you assume these 64,516 square kilometers (64 billion square meters) were to have an output of 100 watts per meter, at 7.0 hours per day at 100 watts-hours per hour per square meter, this array would throw off 45 billion kilowatt-hours per day, or 395 trillion kilowatt-hours per year.
This imputes a constant 24-7 supply of 1,882 gigawatts, or 1.8 terawatts of electric power. The US draws about 450 gigawatts (or .45 terawatts) of electric power, or by these reckonings 24% of total global electrical output. That sounds plausible.
It’s important to note that at 6.4 billion people on the planet, this 64,000 square kilometer area would only represent an area of 10 square meters per person (that’s about 100 square feet, Jackson) - not much space to replace every electrical generating system on earth - nor much to double it.
Apparently in the latest report, the U.K. Parliament (this time around) is not going to support the construction of hundreds of gigawatts of solar fields in North Africa and the Middle East, delivering electric power on a continental scale via a new trans-Mediterranean grid using advanced-technology underground HVDC transmission lines.
For information on mega-solar concentrator potential, read our posts “Nevada Solar One,” “Solel’s Solar Thermal,” “Thermal Circulation Systems,” “Solar Thermal Storage,” “Thermal Voltaic Power,” and “Serious Megawatts.”
To get an idea of the potential of HVDC transmission, read “Life in the Electric Age,” and “Saharan Solar Power.”
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| Trough solar thermal collectors (1 axis). (Photo: TREK UK) |
Here is the text of the press release from TREC-UK, a group supporting the proposal for a trans-mediterranean HVDC power grid connected to massive new solar concentrator fields:
“A plan to supply the whole of Europe with clean solar power from desert regions in North Africa and the Middle East has now been debated in the House of Commons.
On Thursday, Dr Howard Stoate, MP for Dartford, described how, every year, each square kilometre of hot desert receives solar energy equivalent to 1.5 million barrels of oil. Multiplying by the area of deserts worldwide, this is several hundred times the entire energy consumption of the world. The key technology for tapping in to this cornucopia is the simple proven technique of “concentrating solar power” (CSP): using mirrors to concentrate sunlight to create heat and then using the heat to raise steam to drive turbines and generate electricity, just like a conventional power station. Solar heat can be stored so that electricity generation can continue at night.
Using CSP, less than 1% of the world’s deserts could generate as much electricity as the world is currently using. And it is feasible and economic to transmit solar electricity for 3000 km or more using highly-efficient ‘HVDC’ transmission lines. It has been calculated that 90% of the world’s population lives within 2700 km of a hot desert and could be supplied with solar electricity from there.
Quite apart from the transmission of solar energy throughout Europe, the Middle East and North Africa, the proposed ‘HVDC’ Supergrid would reduce wastage by allowing electricity to be transmitted from areas of surplus to areas of need, it would increase energy security because temporary shortfalls in any area could be covered from elsewhere, and it would help to match variable demands with variable supplies. It would also provide the means of transmitting electricity from large-scale but remote renewable sources such as off-shore wind farms, wave farms, tidal stream generators and the like.
Dr Stoate said “Concentrated solar power is a concept of literally dazzling simplicity. It is an idea so simple, and with such extraordinary promise as a means of power generation, that it seems astonishing that in Europe we are only just waking up to its potential, more than 20 years after its first use in California.”
Responding to Dr Stoate’s speech, energy minister Malcolm Wicks MP said “The world has huge solar resources, on which concentrated solar power technology can clearly draw. … The Government will continue to follow developments in concentrated solar power and long-distance electricity transmission.” He said that Dr Stoate had made several interesting and important points and that he would like to be better informed on the subject.”
March 1st, 2008 at 7:51 am
Insolation in the hottest areas on earth is 8.5kWh/day. Check with NASA or NREL (National Renewable Energy Laboratory).
Now do your number crunching but don’t forget the collector is probably only 20% efficient.
March 1st, 2008 at 2:12 pm
Eric: Assuming you are referencing a per meter figure, then 8.5 kWh per square meter per day at 20% efficiency suggests 1.7 kWh thermal energy would be harvested. We used a figure of 700 watts of electric energy per square meter per day which is probably somewhat lower than yours given the efficiency of converting the thermal energy to electricity will probably be at least 50%. The space required for solar thermal electric power or photovoltaic electricity is not the constraint. The constraint is the cost. Also, in using the thermal energy to heat water to move a steam turbine genset, the other challenge is cooling the water for reuse. Solar thermal power at this scale could never work without recirculating the water.
March 1st, 2008 at 4:29 pm
Do the math using the most efficient solar technology known today, which is Concentrating PV - which is over 40% efficient. These cells are quite expensive so the concentration needs to be high (over 500x), using dishes as opposed to troughs. We can expect this technology to keep increasing efficiency until it reaches over 60%. In addition, the water cooling that keep the operating temperature of the cells down produces hot water than can be used for generating 10-20% more electricity. In 10 years time expect 80% efficiency from PV/T combined technology.
On the size of the area required, remember this is vastly smaller than the combined area of roads, roofs or cars in the world. And the plants can be spread around to many locations close to cities which will also benefit from the abundance of low-cost energy to power factories and homes, making Africa a booming economy.
March 2nd, 2008 at 1:13 pm
Thanks for the promotion of the ideas for using concentrating solar power (and other renewables by the way) from deserts in North Africa and the Middle East to supply part of Europe’s electricity needs.
Our group is called Trans-Mediterranean Renewable Energy Cooperation (TREC), not TREK. It is not a ‘Corporation’ with the capacity to build and operate plants - rather it is an initiative that campaigns for the transmission of clean power from deserts throughout Europe, the Middle East and North Africa. Since it was founded in 2003 by The Club of Rome, the Hamburg Climate Protection Foundation and the National Energy Research Center of Jordan, it has developed the DESERTEC Concept and researched it in cooperation with the German Aerospace Center (DLR).
As well as the UK parliament, policy makers in the European Union are actively considering the concepts.
April 11th, 2008 at 10:57 am
20% total available beam to electric is too high in practice. The power block and cooling equipment as well as site infrastructure (roads etc) take up some space.
The CLFR is probably in the 10-15% land efficiency range when all things are considered. Conservatively taking 10% and 8 kWh/sq m/day that works out to 800,000 kWh/sq km/day, or 292,000,000 kWh/sq km/year.
To get 20 trillion kWh (more than the global current consumption) we’d need about 68500 sq km of high quality desert resource.
The figure looks good -I assumed a bit more than global electric consumption.